AI Dev Config Kit: Ship SaaS 10x Faster

You're building a SaaS with Cursor or Claude Code, and your AI keeps generating Pages Router code when you need App Router, forgetting @supabase/ssr, skipping Stripe webhook signature verification, and ignoring your TypeScript strict mode. You spend more time fixing AI output than you would writing the code yourself.

The AI Dev Config Kit fixes this permanently. It's 29 configuration files, rules, commands, snippets, and templates that teach your AI IDE exactly how to write production-quality code for your Next.js 15 + Supabase + Stripe project. Configure once. Get correct output every time.

What You Get

29 files. 13,000+ lines of battle-tested configuration. Everything organized and ready to drop into your project.

Cursor IDE (10 files)

• .cursorrules -- Master configuration file defining your full tech stack, coding conventions, architecture rules, naming patterns, anti-patterns to avoid, and performance guidelines. This is the brain of your Cursor setup.
• nextjs15-app-router.mdc -- Server Components, Server Actions, App Router routing conventions, metadata API, dynamic routes, parallel routes, intercepting routes, and loading/error patterns. Includes good and bad code examples.
• supabase-auth-db.mdc -- SSR authentication with @supabase/ssr, Row Level Security policies, Drizzle ORM queries, three Supabase client variants (server, browser, admin), middleware session refresh, and realtime subscriptions.
• stripe-payments.mdc -- Checkout Sessions, subscription lifecycle, webhook event handling, Customer Portal integration, idempotency, and price/product configuration. Every Stripe pattern your SaaS needs.
• tailwind-shadcn.mdc -- Tailwind CSS v4 syntax (CSS-first configuration, no tailwind.config.js), shadcn/ui component patterns, theming with CSS variables, dark mode, responsive design, and accessibility.
• typescript-strict.mdc -- Strict mode enforcement, zero any types, Zod validation patterns, type inference from Drizzle and Zod schemas, discriminated unions, the satisfies operator, and generic utility types.
• testing-vitest.mdc -- Vitest configuration, React Testing Library patterns, component tests, Server Action tests, mocking Supabase and Stripe, test organization, and coverage targets.
• deployment-vercel.mdc -- Edge vs Node runtime decisions, ISR and caching strategies, environment variable management, CI/CD pipeline, monitoring, and pre-deployment checklists.
• supabase-queries.json -- 15+ ready-to-use code snippets for common Supabase operations: CRUD queries, auth flows, RLS policy definitions, realtime subscriptions, and storage operations.
• stripe-webhooks.json -- 10+ ready-to-use code snippets for Stripe integrations: checkout creation, subscription management, webhook handlers, Customer Portal redirects, and price lookups.

Claude Code CLI (9 files)

• CLAUDE.md -- Comprehensive project context file (800+ lines) covering your entire tech stack, architecture principles, file structure, coding standards, naming conventions, component patterns, Server Actions, error handling, Supabase integration, Stripe integration, Drizzle ORM, environment variables, testing standards, and anti-patterns. This is the most thorough CLAUDE.md you will find for this stack.
• /setup-project -- Custom slash command that initializes a complete Next.js 15 + Supabase + Stripe project from scratch with the correct folder structure, dependencies, configuration files, and initial boilerplate.
• /add-auth -- Adds complete Supabase authentication: sign-in, sign-up, forgot password, callback handler, middleware with session refresh, protected routes, and RLS policies.
• /add-payments -- Adds Stripe payments: checkout session creation, subscription management, webhook handler with signature verification, Customer Portal, and pricing page.
• /add-crud -- Generates full CRUD operations for any entity: Drizzle schema, RLS policies, Server Actions with Zod validation, API routes, and React components with loading/error states.
• /add-api-route -- Scaffolds a type-safe API route handler with Zod input validation, authentication checks, proper error responses, and TypeScript types.
• /run-tests -- Runs your test suite, identifies untested code paths, generates missing tests, and reports coverage metrics.
• /deploy -- Runs pre-deployment checks (type checking, linting, tests, environment variables) and deploys to Vercel.
• project-conventions.md -- Memory file where Claude Code persists your project-specific decisions, patterns, and preferences across sessions. The AI remembers what you decided last Tuesday.

Shared Resources (4 files)

• .env.example -- Complete environment variable template with documentation for every variable: Supabase (URL, anon key, service role key), Stripe (secret key, webhook secret, publishable key), database URL, and app URL. Copy it, fill in your values, and you are ready to go.
• schema.sql -- Production-ready Supabase database schema with users table, subscriptions table, products table, prices table, and Row Level Security policies for every table. Ready to execute in your Supabase SQL editor.
• middleware-template.ts -- Next.js middleware with Supabase auth session refresh, protected route enforcement, subscription gating, and redirect logic. Handles the tricky cookie management that trips up most developers.
• stripe-webhook-handler.ts -- Complete Stripe webhook handler covering all subscription lifecycle events: checkout completed, subscription created, updated, deleted, invoice payment succeeded, and invoice payment failed. Includes signature verification and idempotent processing.

Documentation (4 files)

• QUICKSTART.md -- Get running in 5 minutes. Prerequisites, step-by-step installation, environment setup, and example prompts to verify everything works.
• CURSOR-SETUP.md -- Detailed Cursor configuration guide: where to place files, how to import snippets, how to verify rules are loaded, and troubleshooting common issues.
• CLAUDE-CODE-SETUP.md -- Detailed Claude Code configuration guide: CLAUDE.md placement, custom command setup, memory file initialization, and workflow examples.
• CUSTOMIZATION.md -- How to adapt the kit to your specific needs: removing unused rules, adding new technologies, customizing conventions, and extending commands.

Also Included

• README.md -- Product overview, complete file listing, comparison tables, and FAQ.
• LICENSE.md -- Commercial license permitting unlimited personal and commercial projects, including client work. Up to 10 developers per license.

Who Is This For?

• Indie hackers and solo developers building SaaS products with Next.js, Supabase, and Stripe who want their AI IDE to generate correct code on the first try instead of requiring constant corrections.
• Small teams (2-10 developers) who need a shared standard for how AI assistants write code in their codebase, so every team member's AI output is consistent and follows the same patterns.
• Developers switching from Pages Router to App Router who are tired of AI assistants defaulting to outdated Next.js patterns like getServerSideProps and the pages/ directory.
• Freelancers and agency developers who build multiple SaaS projects for clients and want a reusable configuration they can drop into every new project to hit the ground running.
• Anyone who has spent more than 30 minutes re-explaining their tech stack to an AI IDE and thought "there has to be a better way." There is. This is it.

Who Is This NOT For?

Transparency matters. This kit is not the right fit for everyone:

• You are not using Next.js, Supabase, or Stripe. The rules and templates are deeply specific to this stack. If you are using a different framework (Remix, Nuxt, SvelteKit) or different services (Firebase, Auth0, Paddle), the majority of the content will not apply.
• You want a complete boilerplate or starter template. This is not a codebase you clone and build on top of. It is a set of configuration files that make your AI assistant smarter. You still write (or prompt) the actual application code.
• You are not using Cursor or Claude Code. The configuration files are formatted specifically for these two tools. While some AI IDEs can interpret .cursorrules files, full compatibility is only guaranteed with Cursor and Claude Code CLI.
• You expect the AI to build your entire app without guidance. This kit dramatically improves AI output quality, but you still need to understand your tech stack and provide meaningful prompts. It makes the AI a better partner, not a replacement for your judgment.

Tech Stack Covered

Next.js 15App Router, Server Components, Server Actions, Metadata API, MiddlewareTypeScript 5.xStrict mode, Zod validation, type inference, zero any typesSupabasePostgreSQL, Auth (SSR), Row Level Security, Drizzle ORM, RealtimeStripeCheckout, Subscriptions, Webhooks, Customer PortalTailwind CSS v4CSS-first config, shadcn/ui, dark mode, responsive designVitestUnit tests, component tests, mocking, coverageVercelDeployment, Edge/Node runtime, ISR, caching, CI/CDDrizzle ORMSchema definitions, migrations, type-safe queries

What Makes This Different?

vs. Free .cursorrules Files from GitHub

FeatureFree GitHub RulesAI Dev Config KitStack specificityGeneric, one-size-fits-allTailored for Next.js 15 + Supabase + StripeRule integrationIndividual files, untested together29 files tested as a complete, coherent systemCode examplesMinimal or noneGood and bad examples for every rule and patternClaude Code supportNoneFull CLAUDE.md + 7 custom slash commands + memoryCode templatesNoneMiddleware, webhook handler, SQL schema, env templateSnippetsNone25+ ready-to-use Supabase and Stripe snippetsDocumentationREADME at best4 detailed guides (quickstart, setup, customization)UpdatesSporadic, if everLifetime updates with every major version bump

vs. SaaS Boilerplates ($199+)

Boilerplates give you a codebase to start from. This kit gives you an AI assistant that understands your patterns. Here is why that matters:

• Boilerplates lock you into their architecture. This kit adapts to yours. You build what you need instead of ripping out what you don't.
• Boilerplates become outdated. AI-generated code uses the latest APIs because the rules teach current best practices, not last year's patterns frozen in a starter repo.
• Boilerplates are a one-time starting point. This kit helps you throughout the entire development lifecycle -- from project setup to deployment, from adding auth to writing tests.
• Boilerplates cost 7-10x more. At $29, this kit costs less than a single hour of developer time and saves you hundreds of hours over the life of your project.

Frequently Asked Questions

Does this work with Windsurf or other AI IDEs?

The Cursor rule files (.cursorrules and .mdc files) follow standard formats that several AI IDEs can interpret. Windsurf, in particular, can read .cursorrules files. However, the kit is tested and optimized specifically for Cursor and Claude Code CLI. The Claude Code configuration (CLAUDE.md, custom commands, memory) is specific to Claude Code and will not work in other tools.

Will this work with my existing project?

Yes. The configuration files are purely additive -- you copy them into your project and they take effect immediately. No code changes required. No dependencies to install. No build step. If your existing project uses Next.js 15 + Supabase + Stripe (or any subset of that stack), the relevant rules will apply right away.

What if I'm not using all three technologies (Next.js + Supabase + Stripe)?

Each technology has its own dedicated rule file. If you are not using Stripe, simply do not copy the stripe-payments.mdc file and the Stripe snippets. The remaining rules work independently. The Customization Guide explains exactly which files to include for your specific stack.

I already have a .cursorrules file. Will this conflict?

The kit's .cursorrules replaces your existing one. However, the Customization Guide walks you through merging your existing rules with the kit's rules so you keep your custom conventions while gaining the kit's stack-specific intelligence.

How is this different from just writing my own CLAUDE.md or .cursorrules?

You absolutely can write your own, and many developers do. The difference is time and depth. This kit represents hundreds of hours of iteration: testing which rule phrasings actually change AI behavior, discovering which anti-patterns the AI needs to be explicitly told to avoid, and structuring the rules so they work together as a system rather than conflicting with each other. You could build this yourself, but it would take weeks of experimentation to reach the same level of effectiveness.

Do I get updates?

Yes, free lifetime updates. When Next.js 16 ships, when Supabase changes their auth API, when Stripe introduces new features -- the kit is updated accordingly and you receive the update through Gumroad at no additional cost. You paid once. You benefit forever.

What if it doesn't work for me?

30-day money-back guarantee, no questions asked. If the kit does not improve your AI development workflow, request a full refund through Gumroad. You will receive your money back promptly. There is zero risk.

Can I use this for client projects?

Yes. The license permits use in unlimited personal and commercial projects, including client work and freelance projects. The only restriction is that you cannot redistribute or resell the configuration kit itself. A single license covers up to 10 developers on the same team.

Money-Back Guarantee

30 days. No questions asked.

Try the AI Dev Config Kit in your project. If it does not noticeably improve the quality and consistency of your AI-generated code, request a full refund through Gumroad within 30 days. You will receive your money back -- no justification needed, no hoops to jump through. The risk is entirely on us, not on you.

Lifetime Updates

Buy once. Benefit forever.

The web development ecosystem moves fast. Next.js, Supabase, and Stripe all release major updates regularly. When they do, the AI Dev Config Kit is updated to reflect the latest APIs, patterns, and best practices. Every update is delivered to you through Gumroad at no additional cost. Your $29 investment today keeps paying dividends for years to come.

What Developers Are Saying

"I was re-explaining my Supabase auth setup to Cursor every single conversation. Dropped in the config kit and it just... knew. First prompt, correct code. That alone was worth the price."

"The Claude Code slash commands are a game changer. /add-auth gave me a complete authentication system in minutes that would have taken me half a day to write and debug."

"I've tried free .cursorrules from GitHub. They're generic and conflict with each other. This kit is cohesive -- everything works together. The difference is night and day."

Stop fighting your AI assistant.
Start shipping your SaaS.

29 files · 13,000+ lines · Cursor + Claude Code · Next.js 15 + Supabase + Stripe
One-time payment · Lifetime updates · 30-day money-back guarantee